Fluid pressure brake



Aug. 24, 1937. E. E. HEWITT FLUID PRESSURE BRAKE 2 Sheets-Sheet 1 FiledJune 30, 1936 w j q 91 lo 19 .2 m 0 m uh 5 hJ Qm n9 1 I LG Q 9 h uco q THE? +3 llllllllll- INVENTOR ELLIS E. HEWITT A'I'I'ORNEY Aug. 24, 1937.E. E. HEWITT FLUID PRESSURE BRAKE 2 Sheets-Sheefi 2 INVENTOR Q/zm/ ELLISE. HEWITT ATTORNEY Filed June 30, 1936 Patented Aug. 24, 1937 rarerFries FLUID PRESSURE BRAKE Ellis E. Hewitt, Edgewood, Pa., assignor toThe Westinghouse Air Brake Company, Wilmerding, Pa, a corporation ofPennsylvania Application June 30, 1936, Serial No. 88,097

8 Claims.

10 straight air control portion lending itself readily to flexible brakecontrol for normal service application of the brakes, and the automaticcontrol portion being employed as a stand-by control equipment forefiecting emergency braking.

15 The straight air control portion of such equipments may be providedwith magnet valve devices at each braking unit for controlling thesupply of fluid under pressure to, and the release of fluid underpressure from, a straight air pipe that is common to the several brakingunits of the train. This arrangement permits rapid changes in thestraight air pipe pressure and assures uniform braking pressures sincethe several brake cylinders are all supplied with fluid under pressurein accordance with the fluid pressure developed in the common straightair pipe. In the case of the automatic brake portion, however, where areduction in brake pipe pressure effects the supply of fluid underpressure to each brake cylinder from the associated auxiliary res--servoir, there is a possibility that differences in pressure within theseveral brake cylinders will result, caused by leakage from the brakecylinders, variations in the piston travel, and the like, and which willproduce difierent braking forces at different points in the train.

Brake valve devices have been provided for controlling such equipmentshaving a self-lap ping valve portion for controlling the straight aircontrol portion of the equipment and a rotary valve portion forcontrolling the automatic portion of the equipment.

It is an object of my invention to provide braking equipment of theabove indicated character that is quick acting both in applying andreleasing the brakes, and that effects a uniform application of thebrakes throughout the train whether initiated by the straight air or theautomatic control portion.

It is a further object of my invention to provide, in a brakingequipment of the above indicated character, means for eiTectingoperation of the self-lapping brake valve portion to give anuncontrolled full brake cylinder pressure during an emergency brakeapplication caused by a reduction in brake pipe pressure.

Other objects and advantages of my invention will be apparent from thefollowing description of one preferred embodiment thereof taken inconnection with the accompanying drawings in which,

Fig. 1 is a diagrammatic view illustrating apparatus comprising onepreferred embodiment of the invention,

Fig. 2 is a sectional View of the brake valve device illustrated in Fig.1,

Fig. 3 is a sectional view taken on the line 3-3 in Fig. 2,

Fig. 4 is a sectional View taken along the line l-4 in Fig. 2,

Fig. 5 is a view taken along the line 55 in Fig. 4,

Fig. 6 is a detail View taken along the line 66 in Fig. 4, and v Fig. '7is a diagrammatic development showing the operation of the brake valvedevice.

Referring to the drawings, the brake cylinder i represents one unit of abrake equipment that may be supplied with fluid under pressure from anauxiliary reservoir 2, associated therewith, by operation of anautomatic valve device 3 upon a reduction in pressure in the brake pipe4 in a well known manner, and which brake cylinder may also be suppliedwith fluid under pressure in accordance with the fluid pressuredeveloped in the straight air pipe 6 that is common to all brakingunits. The pressure in the straight air pipe 8 is controlled byapplication and release magnet valve devices I and 8, respectively,associated with each braking unit, for controlling the suppfy of fluidunder pressure from a main reservoir pipe 5 and main reservoir [2 to thebrake cylinder, and from the brake cylinder to the atmosphere,respectively, and which are in turn controlled by a master controldifferential relay device l3 that is governed in accordance with theoperation of a brake valve device I 4 for effecting the supply of fluidunder pressure from the main reservoir 12 as supplied by a feed valvel5, at a reduced pressure, through a pipe I6 and a control pipe llleading to the upper chamber 25 of the master relay device I3.Conductors valves it? are provided at appropriate positions along thetrain to effect emergency application of the brakes from several pointson the train should such be desired.

The brake valve device l4 may correspond with that disclosed and claimedin United States Patent No. 2,042,112, of Ewing K. Lynn and Rankin J.Bush, issued May 26, 1936, and assigned to the same assignee as thisapplication. The brake valve device I4 (see Fig. 2) comprises a casinghaving a main body portion 2I, a self-lapping 5 valve portion 22, and arotary valve or bracket portion 23, the three portions together defininga pressure chamber 24 that is. in open communication through the pipeand passage Il with the pressure chamber 25 of the master control relayI3.

The self-lapping valve portion 22 is provided with a supply valvechamber 21 to which the feed valve device I5 of the usual type suppliesfluid under pressure at a reduced pressure from the main reservoir I2through main reservoir pipe 9 and pipe and passage I 6. A supply valve29 is contained within the supply valve chamber 21 and is slidablydisposed within a bore 3I in the casing to engage a seat 35 provided inthe self-lapping valve portion of the casing. The supply valve 29 issubject to the pressure of a spring 36, one end of which engages thevalve and the other end of which engages a nut 31 screw-threadedlyattached within a bore in the 125 self-lapping valve portion of thecasing.

The self-lapping valve portion or section of the casing is also providedwithin a cylinder 38, which is open at one end to the pressure chamber24, the other end of the cylinder being closed by an adjusting member 4!screwthreadedly attached within a bore in the selflapping valve casingportion. The adjusting member 4| is provided with a central bore 42which at its outer end is adapted to receive a 35 screw-threaded capmember 43.

Operatively mounted in the cylinder 38 adjacent its open end is amovable abutment in the form of a piston 44 having a stem 45, slidablyguided by the adjusting member M with- 40 in the inner end of the bore42. At one end of the piston 44 is a chamber 46 which is constantly opento' the atmosphere through the exhaust port 41. A coil spring 48 iscontained within the chamber and is interposed between 45 and engagesthe inner face of the piston 44 and the inner face of the adjustingmember 4|.

A release valve chamber 49 is provided within the piston 44 that is inopen communication with the pressure chamber 24 through a pas- 50 sage5!. A release valve 52 is contained within the valve chamber 49 and isadapted to seat on the valve seat 53 formed on the piston, and which isoperated to control communication between the valve chamber 49 and thechamber 48 55 through connecting passages 54 in the piston stem 45. Therelease valve is provided with a stem 55, the small end of which slideswithin a bore in the stem of the piston 44 and the larger end of whichis provided with a collar 55, which 0 slidably engages the piston withinthe central bore 51 and is subject to the pressure of the release valvespring 58 interposed between the engaging collar 56 and the annularflange 59 on the piston. Outward movement of the valve 5 relative to thepiston 44 is limited by the collar 56 which engages a stop flange 6|that is secured to the piston 44.

A mechanism is provided for controlling the operation of the supplyvalve 29 and the release valve 52 comprising spaced levers 62 that arepivotally mounted intermediate their ends on a pin 63 supported in aplunger 64 that is slidably guided within a bore 85 in the casing of theself-lapping valve portion 22.

The lower ends of the spaced levers 62 are connected together by a pin66 which is loosely mounted within a roller 61 that is adapted tooperate to engage the outer end of the release valve stem 55. The upperend of the spaced levers 62 are connected together by a pin 58 on whichone end of the operating lever 69 is pivotally mounted, the opposite endof the rod operatively engaging the supply valve 29 within a recess IIformed in its face.

For the purpose of operating the plunger 64 toward the right, there isprovided an operating cam 72, mounted upon a shaft 73, that is carriedin an upper bearing I4 and a lower bearing I5 and is arranged to beoperated by the brake valve handle I5. As the handle I6 is movedprogressively from its release position toward full service applicationposition the cam I2 forces the plunger 54 progressively toward theright.

It will be appreciated that the force of the release valve spring 53 isless than the force of the supply valve spring 36 which is less than theforce of the regulating spring 48. When the cam I2 and the plunger 64are in their release positions, as shown in Fig. 2, the spring 45 forcesthe supply valve 29 toward the left to its seated position and thespring 58 forces the release valve 52 toward the left to its unseatedposition.

Inserted between the surface of the cam 72 and the end of the plunger 54is one end of a lever 17, (see Figs. 2 to 5 inclusive) the other end ofwhich is provided with openings through which extend a shaft IS, thelower end of which is pivotally supported within a bore 19 in a bracket82 extending inwardly from the wall of the casing. The upper end of theshaft l8 eX- tends through a bore 83 in the top of the casing section. Aspring 84 is provided in the bore "I9, one end of which engages the endof the bore and the other end of which engages the lower end of theshaft I8 to force it upwardly. A collar 85 is provided on the shaftadjacent the bore 83 to retain the shaft I8 within the bore IS. A finger85 is fastened to the rod I9 by means of a pin 86 to eifect movement ofthe lever TI in a counterclockwise direction as viewed in Fig. 4 and themovement of the plunger 64 toward the right as viewed in Figs. 2 and 4,upon a corresponding movement of the shaft I8. A piston chamber 81 isprovided in the upper part of the casing portion of the self-lappingvalve section that is in constant open communication with the brake pipe4 and which contains a piston 88 having a stem 89 that is connected by apin 9! to one end of a crank 92, the other end of which is keyed to theshaft I8. A spring is provided within the casing about the stem 89, oneend of which engages the end of the casing and the other end of whichengages the piston 88 for urging the piston 88 toward the right upon thereduction in pressure within the brake pipe 4 and the piston chamber 81below its predetermined value.

To the lower end of the shaft beneath the bearing '55 a rotary valve 93is attached within the valve chamber 94 that is in constantcommunication with the main reservoir I2 through passage and pipe I6 andthe main reservoir pipe 9. When the brake valve handle It is in itsrelease position or in any position within the self lapping zone therotary valve 94 is also in communication through a restricted port 95 inthe rotary valve 93 with the brake pipe and passage 4. A cavity 96 isprovided in the rotary valve 53 for effecting a reduction in brake pipepressure at a service rate when the handle 15 is in a service positionfor the rotary valve 93. A cavity 98 is provided in the rotary valve 93for effecting a reduction in brake pipe pressure at an emergency ratewhen the handle '16 is in emergency position.

The master control differential relay device I3 comprises a casingcontaining the aforementioned chamber 24 in the upper portion thereofand a chamber I04 in the lower portion, the two chambers being separatedby a diaphragm I535. The diaphragm is provided with an upwardlyextending stem I06 that carries a movable contact member I01 that isadapted to engage a fixed contact member 38 for controlling theoperation of the release magnet valve device 8 and with a downwardlyextending stem I09 carrying a movable contact member H2 for engaging afixed contact member II3 for controlling the operation of theapplication magnet valve devices 1. Centering springs I M and I I5 areprovided on the upper and lower sides, respectively, of the diaphragmI65, the lower spring H5 having a slightly greater force than the springI I4 so as normally to maintain the contact members IN and its inengagement when no pressure exists on either side of the diaphragm I05.

The application magnet valve device '3 comprises a casing containing anapplication valve chamber H6 that is in constant open communication withthe main reservoir pipe 9, and a chamber II! that is in constant opencommunication with the straight air pipe t. An application valve IIB iscontained within the chamber H5 and is urged toward its seat by a springI 59 therein, and is adapted to be urged downwardly from its seat by amagnet I22 in the upper part of the casing.

The release magnet valve device 6 comprises a chamber I23 that is inconstant open communication with the straight air pipe 8, and a chamberI24 that is in constant open communication with the atmosphere throughan exhaust port I25. A release valve I26 is provided within the chamberI23 and is urged toward its seat by a spring I2? therein, and is adaptedto be forced downwardly from its seat by a magnet I28 in the upper partof the casing.

The automatic valve device it comprises a casing containing a pistonchamber I29 containing a piston I3I having a stem I32 extendingtherefrom into a valve chamber I33 on the other side of the piston I3Iand operatively engaging a pilot slide valve I35 and a main slide valveits contained within the slide valve chamber I33. 'A port I3? isprovided in the main slide valve i36 that is adapted to be uncovered bymovement of the pilot valve I35 toward the left to eiiect communicationbetween the slide valve chamber I33 and pipe I39 through port I38 uponmovement of the main valve 336 toward the left to bring the port I31into registration with the port 538. A cavity I42 is provided in themain slide valve i555 that, in the illustrated position of the slidevalve, effects communication from pipe 539 to the atmosphere throughexhaust port 543. A graduating stem I44 is provided within a bore in thecasing of the automatic valve device having a flange I45 to limit saidmovement toward the right, and is urged toward its illustrated positionby a spring I46, one end of which engages within a cavity in the casingand the other end of which engages within a cavity in the graduatingstem.

The conductors valve It comprises a casing providing a chamber I5I thatis in constant open communication with the brake pipe 4, and a chamberI52 that is in constant open communication with the atmosphere throughexhaust port I53. A valve I54 is provided within the chamber I5 I, andis urged to its rib seat I55 by a spring I56 contained within thechamber I5I, and is provided with an upwardly extending stem I51 thatextends through a bore in the casing, and the upper end of which engagesa valve lever I58 that is pivotally mounted on a pin I59 in a bracketextending upwardly from the casing. An operating lever I62 is providedmounted on a pin I63 in a bracket extending upwardly from the casing andis adapted upon movement in either position from its illustratedposition to move thev valve lever I58 downwardly against the stem I51 toforce the valve I54 from its seat and effect communication from thebrake pipe 4 to the atmosphere through the exhaust port I53.

Charging the system Fluid under pressure flows from the main reservoirI2 to the main reservoir pipe 9 to charge the application valve chamberH6. and through pipe it? as supplied by the feed valve device I 5 tocharge the supply valve chamber 21 in the self-lapping portion of thebrake valve device. Fluid under pressure also flows from the pipe I6through the rotary valve chamber 94 of the brake valve device, therestricted port 95, to charge the brake pipe 4. From the brake pipe 4fluid under pressure flows to the piston chamber Bl in the upper portionof the brake valve device, to charge this chamber and force the piston88 toward the left against the bias of the spring 90. Fluid underpressure also flows from the brake pipe 4 to the piston chamber I29 ofthe automatic valve device 3 and through feed groove I 64 to charge themain slide valve chamber I33 and the auxiliary reser voir 2. The valvechamber I59 of the conductors valve E8 is also charged from the brakepipe 4.

With the various parts of the equipment in their illustrated or releasepositions, no pressure will exist in the chambers 24 or H14 of themaster relay device I3 and the contact members I 01 and I08 will be inengagement due to the greater force of the spring I I5 than of thespring I I4. A circuit is thus completed from the battery I65 throughconductor I56, the relay contact members I01 and I68, conductor I67, thewindings of the magnets I28 of the several release magnet valve devices8, to ground at 568 and to the grounded terminal I69 of the battery I65,thus energizing the magnet I28 and forcing the release valve I26downwardly from. its seat to effect communication between the straightair pipe 6 and the atmosphere through release valve chamber I23, chamberI24, and the exhaust port I25.

Operation If the operator wishes to make a service application of thebrakes the handle I6 of the brake valve device I4 is moved from itsrelease position an. amount depending upon the degree of application ofthe brakes desired. Upon the initial movement of the handle from itsrelease position the sloping surface of the cam I2 urges the lever 11away from'the finger 85, as viewed in Fig. 4, against the plunger ii i,forcing this plunger to ward the right as viewed in Figs. 2 and 4.

The first part of this movement eifects the compression of the releaseValve spring 58 and forces the release valve 52 to its seat, closingcommunication between the pressure chamber 24 and the atmosphere throughthe passages SI, 54,

'75 cylinder I, through chambers H6,

and the exhaust port 41. Further movement of the plunger 64 toward theright causes the spaced levers 62 to pivot about their lower ends,further movement of the roller 61 being prevented by the stiffness ofthe regulating spring 48, thus causing the rod 69 to force the supplyvalve 29 against the compression of the supply valve spring 36 to opencommunication between the main reservoir pipe and passage I6 and thepressure chamber 24 through the supply valve chamber 21, thus supp-lyingfluid under pressure from the main reservoir I2 through the pressurechamber 24 to the chamber 25 in the upper part of the master relay valvedevice I3.

The pressure established in the pressure chamber 24 of the brake valvedevice and in the chamber 25 of the master relay device I3 is dependentupon the degree of movement of the brake valve lever 16 and of theplunger 64 from their release positions, since, when the pressure withinthe chamber 24 increases due to the flow of fluid thereto through thesupply valve chamber 21, a like pressure is exerted on the chamber sideof the piston 44 in opposition to the pressure exerted by the regulatingspring 48. This pressure continues to build up until it becomessufiicient to force the piston 44 toward the right, thus relieving thepressure on the roller 61 and permitting the supply valve spring 66 toforce a rod 69 toward the left, pivoting the lever 62 about the pivot 63and moving the supply valve 29 into engagement with its seat 35.

The amount of pressure on the chamber side of the piston 44 that isnecessary to effect sufficient movement of the piston 44 to cause thesupply valve 29 to seat, is dependent upon the amount of movement of theoperating lever 16 and of the plunger 64 from their release positions.The greater the movement of the operating lever 16 from its releaseposition, the greater will be the amount of movement of the pivot pin 63toward the right, and consequently, the greater will be the compressionof the regulating spring 48 necessary to permit movement of the lever 62and of the rod 69 to effect the seating of the supply valve 29. It willbe apparent therefore that the brake valve device is self-lapping on apressure basis, the degree of fluid pressure within the pressure Chamber24 necessary to effect movement of the valves to lap position beingdependent upon the amount of movement of the operating lever 16 from itsrelease position.

Fluid under pressure thus supplied to the chamber 25 of the relay deviceI3 forces the diaphragm I05 downwardly against the bias of the spring Ii5, separating the contact members I01 and I08 and interrupting theabove traced circuit to the winding of the magnet I28 of the releasemagnet valve device 8, thus permitting the release valve I26 to beforced to its seat by the spring I21 and close communication between thestraight air pipe 6 and the atmosphere through exhaust port I25. At thesame time the contact member I I2 is brought into engagement with thecontact member I I3, thus closing a circuit extending from the positiveterminal of the battery I65 through conductor I66, the contact members II2 and H3, conductor I12, the winding of the magnet I22 of theapplication magnet valve devices 1, to ground at I68, and to thegrounded terminal I69 of the battery I65. The magnet I22, thusenergized, forces the application valve I I8 downwardly against the biasof the spring I I9 to open communication between the main reservoir pipe9 and the brake I11, straight air pipe 6, past the double check valveI13 in its lower or illustrated position, and brake cylinder pipe I14.

As fiuid under pressure is thus supplied to the straight air pipe 6 andthe several brake cylinders I through the several application magnetvalve devices I associated vvith the several braking units of the train,and to the chamber I04 of the master relay control device I1, thedifferential pressures in the chambers I04 and 25 decreases until thebrake cylinder pressure has built up sufficiently that the pressurewithin the chamber I04 is sufficient to move the diaphragm I05 upwardlyto separate the contact members H2 and H3 and deenergize the winding ofthe magnets I22 of the application magnet valve devices 1, permittingthem to seat under the bias of the springs II9 to close communicationfrom the main reservoir pipe 9 to the straight air pipe 6. So long asthe pressure in the chambers 25 and I04 corresponds sufiiciently thatthe contact members I01 and H2 are both out of engagement with thecontact members I08 and H3, respectively, both the application valve H8and the release valve I26 remain in their lap positions and the brakecylinder pressure corresponds to the pressure within the pressurechamber 24 of the brake valve device and chamber 25 of the master relaycontrol device I3.

If the operator wishes to-release the brakes the handle 16 is moved torelease position, thus moving the cam 12 away from the plunger 64 andpermitting the release valve spring 56 acting against the release valvestem 55 to force the rollor 61 and the spaced lever 62 toward the leftto unseat the release valve 52 and permit the flow of fluid underpressure from the pressure chamber 24 to the atmosphere through thepassages 5|, 54 and the exhaust port 41', and consequently, from thechamber 25 of the master relay control device I3.

Upon such release of fluid under pressure from the chamber 25 thediaphragm I05 moves upwardly to its illustrated position by the greaterpressure existing in the chamber I04, causing enl gagement of thecontact members I01 and I08 and the completion of the above tracedcircuit through the winding of the magnet I28 of the release magnetvalve device 8, thus energizing the magnet I28 and forcing the releasevalve 526 downwardly from its seat against the bias of the spring I21 toeffect communication between the brake cylinder I and the atmospherethrough the straight air pipe 6, chambers I23 and I24 of the releasemagnet valve device 8, and exhaust port I25.

'If the self-lapping portion of the equipment fails for any reason,such, for example, as failure of battery power, an automatic serviceapplication of the brakes may be made by moving the brakevalve lever 15from release position, through the self-lapping service applicationzone, to the automatic service application position to bring the cavity96 in the rotary valve 93 to a position to effect communication from thebrake pipe 4 to F the atmosphere to effect .a reduction in brake pipepressure at a service rate. This reduction in brake pipe pressure and inthe pressure within the piston chamber I21 of the automatic valve device3 causes the piston I64 to be moved by the greater pressure on the slidevalve chamber side of the piston toward the left into engagement withthe graduating stem I45, the piston stem I32 moving the graduating slidevalve I35 to uncover the end of the port I31 through the main slidevalve I36 and the finger I15 on the piston stem I32 engaging the end ofthe main slide valve I33 and moving it toward the left to bring the portI3I therein into registration with the port I33 in the slide valve seat,thus effecting communication from the auxiliary reservoir 2 throughauxiliary reservoir pipe I34, slide valve chamber I33, pipe I39, pastthe double check valve H3 in its raised position, and through brakecylinder 10 pipe H3 to brake cylinder I. As the pressure within theauxiliary reservoir 2 and in the slide valve chamber I33 is thus reducedto a value corresponding to the pressure within the piston chamber I29the piston 836 will be moved slightly 15 toward the right so that themain slide valve I36 will lap the port I38 to close communication fromthe auxiliary reservoir 2 to the brake cylinder I and thus effect abrake cylinder pressure corresponding to the amount of reduction in 20brake pipe pressure in a well known manner.

If the operator wishes to make an automatic emergency application of thebrakes, the handle i6 is moved to the automatic emergency applicationposition, thus bringing cavity 33 in the rotary valve 93 to a positionto eiiect communication from a brake pipe 4 to the atmosphere throughexhaust port 91 at an emergency rate, thus creating a greater pressuredifferential between the pressures on the two sides of the piston 30 I3Iof the automatic valve device 3, so that the pressure on the slide valveside of the piston will be sufficient to force the piston against thegraduating stem I44 and compress the graduating spring I 46 to move themain slide valve i36 to- 35 ward the left sufiiciently that the end ofthe valve I36 uncovers the port I38 and effects a more rapid supply offluid under pressure from the auxiliary reservoir 2 to the pipe 539 thanis effected when the air is supplied through the port 40 I31 in the mainslide valve. When the pressure in the auxiliary reservoir 2 and the mainslide valve chamber I33 has reduced sufilciently to eiiect a substantialbalance of pressure on the two sides of the piston I3I the piston willmove slightly toward the right to again lap the port I38 and closecommunication between the auxiliary reservoir 2 and the brake cylinderI.

If the straight air portion of the brake. valve device IQ is inoperative condition, the movement 50 of the handle 15 as above describedcauses the cam I2 to actuate the self-lapping portion of the brake valvedevice to supply fluid under pressure to the straight air pipe 3 at afaster rate and to a higher pressure. than supplied to the pipe l39,

55 thus causing the double check valve I73 to be held in its lowerposition to permit the supply of fluid under pressure from the straightair pipe 3 to the cylinder I. If, for any reason, the selflappingportion of the brake valve device l3 fails to operate as desired tosupply fluid under pressure to the straight air pipe 6, fluid underpressure will be. supplied to the brake cylinder from the pipe I39 pastthe check valve H3 in its upper position.

65 If the operator wishes to release the brakes after an automaticapplication the handle '16 will be returned to release position toeffect the supply of fluid under pressure from the main reservoir I2 tothe brake pipe 4 through the restricted 70 port 95 in the rotary valve33 in the manner above described for charging the system. As thepressure builds up in the brake pipe 3 it will correspondingly build upin the piston chamber I29 of the automatic valve device 3, thus forcingthe 75 piston I3I towards its illustrated position and efiectingmovement of the main slide valve I36 to its illustrated position toeffect communication from the brake cylinder I to the atmosphere throughthe brake cylinder pipe H4, pipe I39, port I38, the cavity M2 in themain slide valve 436, and to the atmosphere through exhaust port Hi3.

If, for any reason, the conductor or trainmen on any of the cars of thetrain wish to make an emergency application of the brakes, the operatinglever Hit of the conductors valve on a car will be moved in eitherdirection from its illustrated position, thus forcing the valve leverI58 downwardly against the stem I57 of the valve I54 to force the valvefrom its seat and effect communication to the atmosphere from the brakepipe 4 to cause a reduction in brake pipe pressure at an emergency rate.As the brake pipe pressure is reduced, the pressure within the pistonchamber E29 of the auxiliary valve device 3 and also within the pistonchamber 87 of the brake. valve device It is correspondingly reduced. Thereduction in pressure in piston chamber 828 will effect the operation ofthe automatic valve device 3 in the manner above described to supplyfluid under pressure to the brake cylinder through pipe I 33.

The reduction in pressure in the. piston chamber 3i of the brake valvedevice M- permits the spring 93 to force the piston 33 toward the right,thus actuating the lever 92, shaft I3, and the lever ii in acounter-clockwise direction as viewed in Figs. 3 and 4 to force theplunger 64 toward the right as viewed in Figs. 2 and 4 to effect a fullservice application of the brakes through the self-lapping portion ofthe brake valve device M in the-manner above described for a serviceapplication. Fluid under pressure is thus supplied to the straight airpipe 6 and will ordinarily build up within the straight air pipe 8 at afaster rate and to a higher degree than within the pipe I39, thuseffecting the supply of fluid under pressure to the brake cylinder Ifrom the straight air pipe 3, the check valve I'l3 moving away from thesupply having the greater pressure. Upon a subsequent increase in brakepipe pressure to its normal value the pressure within the piston chamberI29 of the auxiliary Valve device 3 and the piston chamber 3? in thebrake valve device I4 will be correspondingly increased, the piston I 3Ibeing moved to its illustrated or release position and the piston 83being moved to its illustrated position against the bias of the spring93 to permit the lever ll to be moved in a clockwise direction againstthe surface of the cam I2, the several parts of the self-lappingmechanism being returned to their illustrated or release positions bythe force. of the springs 36, 5S, and 48 as above described.

While one illustrative embodiment of the invention has been described indetail, it is not my intention to limit its scope to that embodiment orotherwise than by the terms of the appended claims. 3

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a brake equipment for vehicles having a straight air portion andan automatic portion including a brake pipe, in combination, a manuallyoperable brake valve device having .a selflapping portion forcontrolling said straight air portion and a valve for controlling brakepipe pressure to control said automatic portion, and means comprising aspring pressed abutment subject to brake pipe pressure for actuating theself-lapping portion of said brake valve to a brake applying positionupon a reduction in brake pipe pressure.

2. In a brake equipment for vehicles, in combination, means foreffecting straight air application of the brakes, means including abrake pipe for efiecting automatic application of the brakes, a brakevalve device having a self-lapping portion, a rotary valve portion, andmanual means for operating said two valve portions, and automatic meanssubject to a reduction in brake pipe pressure for operating saidself-lapping portion.

3. In a brake equipment for vehicles, in combination, a plurality ofbraking units having a brake cylinder, a straight air portion forcontrolling the supply of fluid under pressure to said brake cylindercomprising a straight air pipe common to all braking units and magnetvalve means associated with each unit for controlling said straight airpipe pressure, an automatic portion for controlling the supply of fluidunder pressure to said brake cylinders comprising a brake pipe common toall braking units and an automatic valve device associated with eachunit, a brake valve device for controlling straight air pipe pressureand brake pipe pressure, and automatic means responsive to a reductionin brake pipe pressure for actuating said brake valve device ioreffecting the supply of fluid under pressure to said straight air pipe.

4. In a brake equipment for vehicles, in combination, a plurality ofbraking units each including a brake cylinder, means including a brakepipe and an automatic valve device associated therewith for controllingthe supply of fluid under pressure to said brake cylinder, meansincluding a straight air pipe for controlling the supply of fluid underpressure to said brake cylinders, magnet valve devices associated witheach braking unit for controlling straight air pipe pressure, manuallyoperable valve means for controlling said magnet valve devices and brakepipe pressure, and automatic means responsive to a predeterminedreduction in brake pipe pressure for controlling said valve means tooperate said magnet valve devices to effect a straight air applicationof the brakes independently of the movement of said manually operablemeans from its release position.

5. In a brake equipment for vehicles, in combination, a plurality ofbraking units each including a brake cylinder, means including a brakepipe and an automatic valve associated with each brake cylinder, forcontrolling the supply of fluid under pressure to said brake cylinder,means including a straight air pipe for controlling the supply of fluidunder pressure to said brake cylinders, a manually operable brake valvedevice having a portion for controlling straight air pipe pressure and aportion for controlling brake pipe pressure, and automatic meanscontained Within said brake valve device and responsive to apredetermined reduction in brake pipe pressure for actuating said brakevalve device to effect the supply of fluid under pressure to saidstraight air pipe.

6. In a brake equipment for vehicles, in combination, a plurality ofbraking units each including a brake cylinder, means including a brakepipe common to all braking units and an automatic valve associated witheach brake cylinder for controlling the supply of fluid under pressureto said brake cylinders, means including a straight air pipe forcontrolling the supply of fluid under pressure to said brake cylinders,a brake valve device having a self-lapping portion and a portion f0):controlling brake pipe pressure, manually operable means for operatingsaid brake valve device, and means subject to brake pipe pressure andnormally held thereby in an inactive position for actuating saidself-lapping portion to effect a straight air application of the brakesupon a predetermined reduction in brake pipe pressure.

'7. In a brake equipment for vehicles, in combination, a plurality ofbraking units each including a brake cylinder, means including a brakepipe common to all braking units and an automatic valve deviceassociated with the several brake cylinders for controlling the supplyof fluid under pressure to said brake cylinders, means including astraight air pipe for controlling the supply of fluid under pressure tosaid brake cylinders, a manually operable brake valve device having aself-lapping portion for controlling straight air pipe pressure and aportion for controlling brake pipe pressure, and a cylinder thereinsubject to brake pipe pressure and containing a movable abutmentoperatively connected to said self-lapping portion, said abutment beingsubject on one side to a constant force and on the other side to brakepipe pressure and operative upon a predetermined reduction in brake pipepressure to actuate said self-lapping portion to full applicationposition.

8. In a brake equipment for vehicles, in combination, a brake cylinder,an automatic brake portion including a brake pipe and an automatic valvedevice-for controlling the supply of fluid under pressure to said brakecylinder, a self-lapping portion including a straight air pipe forcontrolling the supply of fluid under pressure to said brake cylinders,a brake valve device having a manually operable shaft, a valve actuatedthereby for controlling brake pipe pressure, a cam thereon andself-lapping valve means including a plunger actuated by said cam forcontrolling said straight air pipe pressure, means disposed between saidcam and said plunger, and actuating means therefor for operating saidself-lapping valve means to application position upon a reduction inbrake pipe pressure.

ELLIS E. HEWITT.

